/*
 * Copyright 2025 LinQingYing. and contributors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * The use of this source code is governed by the Apache License 2.0,
 * which allows users to freely use, modify, and distribute the code,
 * provided they adhere to the terms of the license.
 *
 * The software is provided "as-is", and the authors are not responsible for
 * any damages or issues arising from its use.
 *
 */

package org.cangnova.cangjie.psi.psiUtil

import org.cangnova.cangjie.name.*
import org.cangnova.cangjie.name.ClassId
import org.cangnova.cangjie.psi.CjClassLikeDeclaration
import org.cangnova.cangjie.psi.CjFile

internal object ClassIdCalculator {
    fun calculateClassId(declaration: CjClassLikeDeclaration): ClassId? {
        var CjFile: CjFile? = null
        val containingClasses = mutableListOf<CjClassLikeDeclaration>()

        for (element in declaration.parentsWithSelf) {
            when (element) {
                is CjClassLikeDeclaration -> {
                    containingClasses += element
                }
                is CjFile -> {
                    CjFile = element
                    break
                }
            }
        }

        if (CjFile == null) return null
        val relativeClassName = FqName.fromSegments(
            containingClasses.asReversed().map { containingClass ->
                containingClass.name ?: SpecialNames.NO_NAME_PROVIDED.asString()
            },
        )

        return ClassId(CjFile.packageFqName, relativeClassName, isLocal = false)
    }
}
